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Re: Using multi-row technique with COPY

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Simon Riggs <simon(at)2ndquadrant(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Using multi-row technique with COPY
Date: 2005-11-29 19:50:35
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Lists: pgsql-hackers
Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > One idea for default behavior would be to use EXCLUSIVE when the table
> > is zero size.  I think that would do pg_dump and most of the user cases,
> > and of course users could override the default by using a keyword.  We
> > could emit a NOTICE if an an exclusive lock is used without an EXCLUSIVE
> > keyword.  One problem I see is that there is no way to insure zero size
> > without a lock that blocks other writers.  Is that reliable?
> No, and if you try to upgrade your lock after checking, you create a
> deadlock problem.
> Something that would probably be reasonable, and require *no* weird new
> syntax, is to shortcut in a COPY into a table created in the current
> transaction.  I believe we still keep a flag in the relcache indicating
> whether that's the case ...

So if the table is created in the current transaction, we don't log? 
Yes, I guess, but do we want to propogate that into pg_dump output?  I
would think not.

  Bruce Momjian                        |
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  +  If your life is a hard drive,     |  13 Roberts Road
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